/*
 * RELIC is an Efficient LIbrary for Cryptography
 * Copyright (C) 2007-2012 RELIC Authors
 *
 * This file is part of RELIC. RELIC is legal property of its developers,
 * whose names are not listed here. Please refer to the COPYRIGHT file
 * for contact information.
 *
 * RELIC is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * RELIC is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with RELIC. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file
 *
 * Implementation of binary field trace function.
 *
 * @version $Id: relic_fb_trc.c 1108 2012-03-11 21:45:01Z dfaranha $
 * @ingroup fb
 */

#include "relic_core.h"
#include "relic_fb.h"
#include "relic_fb_low.h"
#include "relic_error.h"

/*============================================================================*/
/* Public definitions                                                         */
/*============================================================================*/

dig_t fb_trc_basic(fb_t a) {
	int r = 0;
	fb_t t, u;

	fb_null(t);
	fb_null(u);

	TRY {
		fb_new(t);
		fb_new(u);

		fb_copy(t, a);
		fb_copy(u, a);
		for (int i = 1; i < FB_BITS; i++) {
			fb_sqr(t, t);
			fb_add(u, u, t);
		}

		r = u[0] & 1;
	}
	CATCH_ANY {
		THROW(ERR_CAUGHT);
	}
	FINALLY {
		fb_free(t);
		fb_free(u);
	}

	return r;
}

dig_t fb_trc_quick(fb_t a) {
	return fb_trcn_low(a);
}
